Flavouring Extra-Virgin Olive Oil with Aromatic and Medicinal Plants Essential Oils Stabilizes Oleic Acid Composition during Photo-Oxidative Stress

Salvatore Barreca,Teresa Tuttolomondo,Mario Licata,Salvatore La Bella,Andrea Pace,Claudio Leto,Antonella Maggio,Silvestre Buscemi

doi:10.3390/agriculture11030266

Salvatore Barreca, Teresa Tuttolomondo + Show 6 more

Open Access

https://doi.org/10.3390/agriculture11030266

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Abstract

Essential oils (EOs) from medicinal and aromatic plants (MAPs) are well-known as natural antioxidants. Their addition to extra-virgin olive oil (EVOO) can contribute to reducing fat oxidation. The main aim of this study was to improve both food shelf-life and aromatic flavour of EVOO, adding different EOs of Sicilian accessions of common sage, oregano, rosemary and thyme. The morphological and production characteristics of 40 accessions of MAPs were preliminarily assessed. EOs from the most promising accessions of MAPs were analysed by gas-chromatography and mass spectrometry. Photo-oxidative studies of the EOs were carried out and the determination of the EVOO fatty acids obtained from 4 Italian olive varieties was also made. EO content was on average 1.45% (v/w) for common sage, 3.97% for oregano, 1.42% for rosemary and 5.90% for thyme accessions. The highest average EO yield was found in thyme (172.70 kg ha−1) whilst the lowest (9.30 kg ha−1) in rosemary accessions. The chemical composition of EOs was very different in the four MAPs in the study. No significant change of oleic acid percentage was detected in the mixture of EVOO with EO samples. The results seem to highlight the presence of an antioxidant effect of EOs on EVOO.

Highlights

Extra-virgin olive oil (EVOO), an appreciated food especially in the countries of the Mediterranean area, in recent years has gained interest among the consumers in North America and Northern Europe, especially flavoured with spices, herbs or fruits
No significant change of oleic acid percentage was detected in the mixture of extra-virgin olive oil (EVOO) with Essential oils (EOs) samples
This work is an innovative study to assess the quality of flavoured EVOO prepared by adding medicinal and aromatic plants (MAPs) EO

Summary

Introduction

Extra-virgin olive oil (EVOO), an appreciated food especially in the countries of the Mediterranean area, in recent years has gained interest among the consumers in North America and Northern Europe, especially flavoured with spices, herbs or fruits. The production of flavoured olive oils is a traditional practice in Mediterranean area, in order to enhance the sensorial characteristics of the original olive oils and to improve the sensory properties of the foods [1,2]. The success of these innovative products is associated with various health benefits as well as with the taste and flavour. The numerous health benefits of EVOO depend on its particular composition [3,4] It is composed primarily of triacylglycerols (around 97.00–98.00%), minor amounts of free fatty acids and glyceridic compounds, phospholipids and oxidized triacylglycerols and around 1% of unsaponifiable constituents of varied structure and polarity. The addition of naturally occurring antioxidants causes an improvement on the shelf life and nutritional value of oil

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